1. Field of the Invention
The present invention relates to a proportional regulation oil burner of low-pressure air type and, more particularly to improvements in a proportional regulation oil burner of low-pressure air type, which operatively cooperates with a regulating mechanism for feeding an oil amount to vary the opening area of the burner tip end thereby to vary the combustion air amount, and is adapted to atomize the oil such as heavy oil with the combustion air of high temperature.
2. Description of the Prior Art
Conventionally, in the proportional regulation oil burner of low-pressure air type, as shown in FIG. 1, an oil nozzle 4 was disposed at the central portion of the burner body 1, an air nozzle 7 was located on the outer periphery, the oil feed amount from an oil feed opening 6 was regulated through the rotation of a handle 10 to advance or retreat the air nozzle 7 through the operative cooperation therewith, one portion of the air from the combustion air entrance 2 was jetted from the opening portion a through a hole 8 to atomize the oil from the oil nozzle 4. The combusting operation was effected with the combustion air from the opening portion b composed of the air nozzle 7 and the burner external pipe 3.
In the oil burner of said type, when the high-temperature preheating air of 350.degree. C. was used as the combustion air, the oil nozzle 4 was heated. The oil was carbonized on the inner wall of the oil nozzle 4 particularly during the low flow of the oil or during the cut off thereby to perform blocking. The oil, which was adhered on the inner face of the externally expanded conical opening portion 5 of the oil nozzle 4 or on the inner face of the tip end portion 9 of the air nozzle 7, was carbonized and the carbonized oil grows to lose the normal nozzle function. This fact was considerable particularly when heavy oil was used as the fuel.
Therefore, the oil burner of conventional type had a disadvantage in that the heavy oil could not be used when the preheating air of temperature higher than a given temperature was used.